Conventional, prior or known bulletproof door frames usually have a door jamb which includes a built-in door stop. The primary difference between a conventional and a bulletproof construction is in the material used to make the door. The material has a strength which is adequate to stop a particular type of bullet. Thus, different materials and gauges are selected to stop rifles, hand guns, "Saturday Night Specials", and the like. Thus, when a reference is hereinafter made to a bulletproof specification material, it means whatever particular material required to resist the type of bullet in question.
It has been found that if a bullet is directed toward the threat side of a door made of the bulletproof specification material, a dish shaped deformation is formed in the door at the point of impact, and the stopped bullet gives off fragments of shrapnel, which travel along the threat side of the door in a plane parallel thereto. The angle of incidence at which the bullet strikes the door does have some effect upon the angle at which the shrapnel fragments travel away from the door. However, in general, the effect is much less than would normally be expected.
But if the shrapnel fragments strike the door jamb at the crack or space between the door and door jamb, the fragments tend to act as if they were trapped in a guide, and thus they follow the crack and exit into the protected area on the opposite side of the door with enough energy to cause damage. In this regard, the fragments are oftentimes sufficiently small so as to pass freely through the crack or space between the door jamb and the door, thereby presenting a serious risk of injury to persons, or damage to property, located in the protected area on the opposite side of the door.
Thus, it would be highly desirable to have a new and improved bulletproof door and door jamb construction, which prevents, or at least greatly reduces, the possibility of shrapnel fragments traveling which high energy through the crack between the door and the door jamb and entering the protected area behind the door. In this regard, it would be of great importance to have such a new construction, which would not only tend to keep potentially dangerous bullet fragments from entering the protected area, but which would also be relatively inexpensive to manufacture and to install.